CN112403466B - Preparation method of core-shell catalyst for dry reforming of methane and carbon dioxide - Google Patents

Preparation method of core-shell catalyst for dry reforming of methane and carbon dioxide Download PDF

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CN112403466B
CN112403466B CN202011229335.2A CN202011229335A CN112403466B CN 112403466 B CN112403466 B CN 112403466B CN 202011229335 A CN202011229335 A CN 202011229335A CN 112403466 B CN112403466 B CN 112403466B
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catalyst
deionized water
methane
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carbon dioxide
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CN112403466A (en
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孙予罕
王慧
张磊
马春辉
杜洋
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Shanghai Cluster Rui Low Carbon Energy Technology Co ltd
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    • B01J23/86—Chromium
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    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
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    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
    • C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
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    • C01B2203/1041—Composition of the catalyst
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    • C01B2203/1052—Nickel or cobalt catalysts
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    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Abstract

The invention discloses a preparation method of a core-shell catalyst for dry reforming of methane and carbon dioxide, which is characterized in that CaO and a cobalt source/iron source are dissolved into deionized water together for reaction, and then a product Co (OH) is separated by filtration 2 nanosheet/Fe (OH) 2 Nanosheets; dispersing the obtained nanosheets and a metal source M together in deionized water, transferring the nanosheets and the metal source M to a hydrothermal kettle for reaction to obtain CoFeM mixed hydroxide, and roasting to obtain CoFeM mixed oxide; reducing the CoFeM mixed oxide to obtain CoFe @ M x O y A catalyst. Compared with a single-metal Co catalyst, the CoFe alloy catalyst has stronger anti-carbon deposition performance, can effectively inhibit the growth of active metal particles in a high-temperature reforming reaction, and has very excellent catalytic performance, catalytic stability and anti-carbon deposition capability.

Description

Preparation method of core-shell catalyst for dry reforming of methane and carbon dioxide
Technical Field
The invention relates to a CoFe @ M x O y A preparation method of a core-shell catalyst and application of the core-shell catalyst in methane carbon dioxide reforming reaction belong to the technical field of energy utilization and environment.
Background
The reserves of the conventional natural gas in China are quite rich, the main component of the natural gas is methane, and the conversion of the methane into chemicals and liquid fuels with high added values is an important way for efficiently utilizing natural gas resources. The carbon dioxide emission reduction situation in China is quite severe, so that the research on the methane and carbon dioxide reforming reaction has important significance for relieving the energy crisis and reducing the carbon dioxide emission. The CoFe alloy catalyst has wide application prospect in industrial production due to low economic cost and high catalytic activity. However, the CoFe alloy catalyst is deactivated by sintering and carbon deposition during the methane reforming reaction, so that the development of a CoFe alloy catalyst with high stability, carbon deposition resistance and sintering resistance is a main research target.
One of the ways to improve this is to select a suitable vector. The carrier plays an important role in the performance of the catalyst, and not only can disperse the active component, but also can interact and influence the active component, so that the structure, the particle size, the metal dispersion degree and the like of the catalyst are influenced, and the reaction activity, the stability and the carbon deposition resistance of the catalyst are further influenced. The research finds that the TiO 2 And Al 2 O 3 Is the best carrier for the CoFe alloy catalyst to be used for the dry reforming reaction of methane. Supported on TiO 2 Or Al 2 O 3 The CoFe alloy catalyst has excellent stability and carbon deposition resistance because of the active CoFe alloy and TiO 2 Or Al 2 O 3 There is a strong interaction between the carriers.
The coated catalyst with active metal coated by carrier is prepared by ion exchange method, which not only can further strengthen the interaction between active metal and carrier, but also has the confinement effect because the carrier coats active site. Therefore, the carrier coated catalyst prepared by the ion exchange method is expected to solve the key problems of carbon deposition and sintering of the catalyst, which greatly limit the application of the CoFe alloy catalyst in the methane carbon dioxide reaction.
Patent 201610691014.1 discloses a method for promoting carrier and activity by controlling the reduction temperature of active component in the phase transition temperature range of carrier, reducing active metal and utilizing the phase transition induction and structure rearrangement action of carrierThe metal has strong action and is induced to prepare the high-dispersion metal-loaded catalyst. The supported catalyst adopts an impregnation method, wherein the carrier is TiO 2 、Al 2 O 3 And the like, co as an active metal. The catalyst has simple preparation method and easily controlled synthesis conditions. But the active metal of the catalyst prepared by the impregnation method is easy to agglomerate. And its CO 2 And CH 4 The conversion rate of (A) is not high enough, and the carbon deposition resistance and stability are not good enough.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the Co-based supported methane dry reforming catalyst has low conversion rate and poor carbon deposition resistance and stability.
In order to solve the technical problem, the invention provides a preparation method of a core-shell catalyst for dry reforming of methane and carbon dioxide, which is characterized by comprising the following steps:
step 1): dissolving CaO and a cobalt source into deionized water, stirring the mixture in a water bath at room temperature for reaction, and filtering the reaction product to separate Co (OH) 2 Washing the nano-sheets to be neutral by using deionized water, and drying; dissolving CaO and an iron source into deionized water, stirring the solution in a water bath at room temperature for reaction, and filtering the reaction product to separate a product Fe (OH) 2 Washing the nano-sheets to be neutral by using deionized water, and drying;
step 2): mixing the Co (OH) obtained in the step 1) 2 Nanosheet, fe (OH) 2 Dispersing the nanosheets and the metal source M in deionized water, stirring uniformly, transferring the solution to a hydrothermal kettle for reaction, centrifuging, washing the product to be neutral by using the deionized water, and drying to obtain a CoFeM mixed hydroxide;
step 3): roasting the CoFeM mixed hydroxide obtained in the step 2) in a muffle furnace to obtain a CoFeM mixed oxide;
step 4): placing the CoFeM mixed oxide obtained in the step (3) in H 2 And N 2 Is reduced under the atmosphere of mixed gas to obtain CoFe @ M x O y A catalyst.
Preferably, in the step 1), the cobalt source is cobalt nitrate, the iron source is ferrous nitrate, and the adding molar amounts of the cobalt source and the iron source are the same; the mol ratio of CaO to Co or Fe is (0.4-1.2) and the proportion of 1 Co or Fe to the deionized water solution is 1mmol: (1-4) mL.
Preferably, the reaction time in the step 1) is 12-60 h; the drying temperature is 80 ℃ and the drying time is 12h.
Preferably, co (OH) in said step 2) 2 Nanosheet, fe (OH) 2 The molar ratio of Co to Fe in the nanosheets is 7:3; the metal source M is at least one of titanium nitrate, aluminum nitrate and chromium nitrate, and the molar ratio of the metal source M to the sum of the moles of Co and Fe is (0.5-3): 1; the ratio of the sum of the moles of Co and Fe to the deionized water is 1mmol: (1-6) mL.
Preferably, the reaction temperature in the step 2) is 60-180 ℃ and the reaction time is 6-18 h.
Preferably, the roasting temperature in the step 3) is 600 ℃ and the time is 4h.
Preferably, H in said step 4) 2 And N 2 H in the mixed gas atmosphere of 2 And N 2 The volume percentage of the catalyst is 50 percent respectively, the reduction temperature is 400-700 ℃, and the time is 1-8 h.
The invention provides a CoFe @ M prepared by an ion exchange method x O y (M = Ti, al, cr) core-shell catalyst, coFe alloy catalyst has stronger carbon deposition resistance than single metal Co catalyst. And TiO 2 2 The carrier coating active center can not only further strengthen the interaction between the active metal and the carrier, but also play a certain limited protection role because the CoFe alloy active center is coated by the metal oxide carrier. Therefore, the catalyst can effectively inhibit the growth of active metal particles in a high-temperature reforming reaction, and has excellent catalytic performance, catalytic stability and anti-carbon deposition capability.
Compared with the prior art, the invention has the following advantages:
(1) The hydrothermal method can easily control the sizes of Co and Fe by controlling the conditions such as reaction temperature, reaction time and the like, and the sizes of the Co and Fe are far smaller than the sizes of Co and Fe particles of the catalyst prepared by an impregnation method, a coprecipitation method and the like.
(2) The Co and Fe particles of the catalyst prepared by the ion exchange method are small (2-9 nm) and uniform, so that the catalyst has better catalytic performance and stability.
(3) Compared with a supported catalyst, the carrier coated catalyst has higher interface density and stronger metal-carrier interaction, and active species are physically isolated by the carrier and have high stability, so that the catalyst shows more excellent catalytic performance in a dry reforming reaction of methane, and has better catalytic stability and carbon deposition resistance.
(4) The preparation method of the catalyst is simple and feasible, and can be applied to industrial application in a large scale.
Detailed Description
In order to make the invention more comprehensible, preferred embodiments are described in detail below.
For CoFe @ M prepared in example x O y (M = Ti, al, cr) core-shell catalyst and Co, fe supported on TiO prepared in comparative example 2 The evaluation of the use of the supported catalyst for the carbon dioxide reforming reaction of methane was as follows:
0.1g (40-60 meshes) of catalyst and 0.9g (40-60 meshes) of quartz sand are weighed and mixed evenly in H 2 /N 2 Pre-reducing for a certain time at a certain temperature in an atmosphere (50% by volume each and a flow rate of 120 mL/min). After the reduction is finished, the reaction temperature is 850 ℃, and the molar ratio of methane to carbon dioxide in the raw material gas is 1:1,N 2 3% as internal standard. The flow rate of the raw material gas is 150mL/min, the space velocity is 90000 mL/(gh), and the raw material gas directly passes through the catalyst bed layer. CH can be obtained by gas chromatography TCD and calculation with internal standard method 4 ，CO 2 Conversion and products CO and H 2 The ratio of (a) to (b).
Example 1
Firstly, 6.8g of CaO and 29.1g of cobalt nitrate hexahydrate are dissolved into 400mL of deionized water solution together, the mixture is stirred in a water bath at room temperature and reacts for 60 hours, then the product is separated by filtration, washed to be neutral by deionized water, and finally dried in an oven at 80 ℃ for 12 hours to obtain a product Co (OH) 2 Nanosheets. Likewise, 6 will be8g CaO and 28.8g ferrous nitrate hexahydrate are added to the solution and the process is repeated to obtain Fe (OH) 2 Nanosheets.
3.3g and 1.4g of Co (OH) obtained above were taken 2 Nanosheet and Fe (OH) 2 Dispersing the nano-sheets and 45.0g of titanium nitrate into 300mL of deionized water solution, uniformly stirring, transferring the solution into a hydrothermal kettle, and carrying out ion exchange reaction for 18h at the hydrothermal temperature of 180 ℃. And cooling to room temperature, centrifuging, washing to be neutral by using deionized water, and drying in an oven at 80 ℃ for 12 hours to obtain the CoFeTi mixed hydroxide.
And (3) roasting all the obtained CoFeTi mixed hydroxides in a muffle furnace at 600 ℃ for 4h to obtain the CoFeTi mixed oxide.
0.1g of the CoFeTi mixed oxide obtained above was placed in a reactor in H 2 /N 2 Reducing for 2h at the reduction temperature of 700 ℃ in an atmosphere (50 percent by volume and the flow rate of 120 mL/min) to obtain CoFe @ TiO 2 A coated catalyst. Then introducing CO 2 /CH 4 The raw material gas is subjected to methane dry reforming reaction.
The average grain diameter of CoFe alloy particles is 2.1nm through characterization results of XRD, TEM and the like. The evaluation results show that the product has CO 2 Conversion was 86.9%, CH 4 Conversion 91.8%, H 2 The molar ratio/CO was 0.87. The catalytic performance of the catalyst has no obvious change within 500h of reaction, which shows that the catalyst has excellent stability and carbon deposition resistance.
Example 2
Firstly dissolving 2.3g of CaO and 29.1g of cobalt nitrate hexahydrate in 100mL of deionized water solution, stirring in a water bath at room temperature for 12 hours, filtering to separate a product, washing with deionized water to be neutral, and finally drying in an oven at 80 ℃ for 12 hours to obtain a product Co (OH) 2 Nanosheets. Similarly, 2.3g CaO and 28.8g ferrous nitrate hexahydrate are added to the solution, and the above operation is repeated to obtain Fe (OH) 2 Nanosheets.
3.3g and 1.4g of Co (OH) obtained above were taken out 2 Nanosheet and Fe (OH) 2 Dispersing the nano-sheets and 7.5g of titanium nitrate into 50mL of deionized water solution, uniformly stirring, transferring the solution into a hydrothermal kettle, and carrying out ion exchange reaction for 6h at the hydrothermal temperature of 60 ℃. And cooling to room temperature, centrifuging, washing to be neutral by using deionized water, and drying in an oven at 80 ℃ for 12 hours to obtain the CoFeTi mixed hydroxide.
And (3) roasting all the obtained CoFeTi mixed hydroxides in a muffle furnace at 600 ℃ for 4h to obtain the CoFeTi mixed oxide.
0.1g of the CoFeTi mixed oxide obtained above was placed in a reactor in H 2 /N 2 Reducing for 1h at the reduction temperature of 400 ℃ in an atmosphere (50 percent by volume and the flow rate of 120 mL/min) to obtain CoFe @ TiO 2 A coated catalyst. Then introducing CO 2 /CH 4 The raw material gas is subjected to methane dry reforming reaction.
The average grain diameter of CoFe alloy particles can be found to be 4.9nm through characterization results of XRD, TEM and the like. The evaluation results show that the product has CO 2 Conversion 75.1%, CH 4 Conversion 80.9%, H 2 The molar ratio/CO was 0.81. The catalytic performance of the catalyst is not obviously changed within 500 hours of reaction, which shows that the catalyst has excellent stability and anti-carbon deposition capability.
Example 3
Firstly dissolving 4.5g of CaO and 29.1g of cobalt nitrate hexahydrate into 200mL of deionized water solution, stirring in a water bath at room temperature for reaction for 48 hours, filtering to separate a product, then washing with deionized water to be neutral, and finally drying in an oven at 80 ℃ for 12 hours to obtain a product Co (OH) 2 Nanosheets. Similarly, 4.5g CaO and 28.8g ferrous nitrate hexahydrate are added to the solution, and the above operation is repeated to obtain Fe (OH) 2 Nanosheets.
3.3g and 1.4g of Co (OH) obtained above were taken 2 Nanosheet and Fe (OH) 2 Dispersing the nano-sheets and the titanium nitrate in 150mL of deionized water solution together with 22.5g of the titanium nitrate, uniformly stirring, transferring the solution into a hydrothermal kettle, and carrying out ion exchange reaction for 12 hours at the hydrothermal temperature of 120 ℃. When cooled to room temperature, centrifuged and then washed with deionized waterAnd drying the mixture for 12 hours in an oven at 80 ℃ until the mixture is neutral to obtain the CoFeTi mixed hydroxide.
And (3) roasting all the obtained CoFeTi mixed hydroxides in a muffle furnace at 600 ℃ for 4h to obtain the CoFeTi mixed oxide.
0.1g of the CoFeTi mixed oxide obtained above was placed in a reactor in H 2 /N 2 Reducing for 4h at the reducing temperature of 600 ℃ in the atmosphere (the volume percentage is 50 percent respectively, the flow rate is 120 mL/min) to obtain CoFe @ TiO 2 A coated catalyst. Then introducing CO 2 /CH 4 The raw material gas is subjected to methane dry reforming reaction.
The average grain diameter of CoFe alloy particles can be found to be 2.5nm through characterization results of XRD, TEM and the like. The evaluation results show that the product has CO 2 The conversion rate was 89.1%, CH 4 Conversion 93.3%, H 2 The molar ratio/CO was 0.88. The catalytic performance of the catalyst is not obviously changed within 500 hours of reaction, which shows that the catalyst has excellent stability and anti-carbon deposition capability.
Example 4
Firstly dissolving 3.4g of CaO and 29.1g of cobalt nitrate hexahydrate in 300mL of deionized water solution, stirring in a water bath at room temperature for 24 hours, filtering to separate a product, washing with deionized water to be neutral, and finally drying in an oven at 80 ℃ for 12 hours to obtain a product Co (OH) 2 Nanosheets. Similarly, 3.4g CaO was added to the solution along with 28.8g ferrous nitrate hexahydrate, and the above procedure was repeated to obtain Fe (OH) as a product 2 Nanosheets.
3.3g and 1.4g of Co (OH) obtained above were taken out 2 Nanosheet and Fe (OH) 2 Dispersing the nanosheets and 28.1g of aluminum nitrate hexahydrate in 100mL of deionized water solution, uniformly stirring, transferring the solution into a hydrothermal kettle, and carrying out ion exchange reaction for 15 hours at the hydrothermal temperature of 150 ℃. And cooling to room temperature, centrifuging, washing to be neutral by using deionized water, and drying in an oven at 80 ℃ for 12 hours to obtain the CoFeAl mixed hydroxide.
And roasting all the CoFeAl mixed hydroxides in a muffle furnace at 600 ℃ for 4h to obtain the CoFeAl mixed oxide.
0.1g of the CoFeAl mixed oxide obtained above was placed in a reactor in H 2 /N 2 Reducing for 8h at the reduction temperature of 500 ℃ in an atmosphere (50 percent by volume and the flow rate of 120 mL/min) to obtain CoFe @ Al 2 O 3 A coated catalyst. Then introducing CO 2 /CH 4 The raw material gas is subjected to methane dry reforming reaction.
The average grain diameter of CoFe alloy particles is 3.2nm according to characterization results of XRD, TEM and the like. The evaluation results show that the product has CO 2 Conversion was 84.2%, CH 4 Conversion 89.4%, H 2 The molar ratio/CO was 0.85. The catalytic performance of the catalyst is not obviously changed within 500 hours of reaction. Description of CoFe @ Al 2 O 3 The coated catalyst also has excellent stability and anti-carbon deposition capability.
Example 5
Firstly, 5.6g of CaO and 29.1g of cobalt nitrate hexahydrate are dissolved into 200mL of deionized water solution together, the mixture is stirred in a water bath at room temperature for 36 hours of reaction, then the product is separated by filtration, then the product is washed by deionized water to be neutral, and finally the product Co (OH) can be obtained by drying the product in an oven at 80 ℃ for 12 hours 2 Nanosheets. Similarly, 5.6g CaO and 28.8g ferrous nitrate hexahydrate are added to the solution, and the above operation is repeated to obtain Fe (OH) 2 A nanosheet.
3.3g and 1.4g of Co (OH) obtained above were taken out 2 Nanosheet and Fe (OH) 2 Dispersing the nanosheets and 17.9g of chromium nitrate into 200mL of deionized water solution, uniformly stirring, transferring the solution into a hydrothermal kettle, and carrying out ion exchange reaction for 9 hours at the hydrothermal temperature of 90 ℃. When the solution is cooled to room temperature, the solution is centrifuged, washed to be neutral by deionized water, and dried in an oven at 80 ℃ for 12 hours to obtain the CoFeCr mixed hydroxide.
All the CoFeCr mixed hydroxides obtained above were calcined in a muffle furnace at 600 ℃ for 4h to obtain CoFeCr mixed oxides.
0.1g of the CoFeCr mixed oxide obtained above was placed in a reactor in H 2 /N 2 Under the atmosphere (50% by volume, flow rate 120 mL/min), at 600 deg.CReducing for 6h at original temperature to obtain CoFe @ Cr 2 O 3 A coated catalyst. Then introducing CO 2 /CH 4 The raw material gas is subjected to methane dry reforming reaction.
The average grain diameter of CoFe alloy particles can be found to be 4.3nm through characterization results of XRD, TEM and the like. The evaluation results show that the product has CO 2 Conversion 81.6%, CH 4 Conversion was 86.2%, H 2 The molar ratio/CO was 0.83. The catalytic performance of the catalyst is not obviously changed within 500 hours of reaction, which shows that the catalyst has excellent stability and anti-carbon deposition capability.
Comparative example 1
Dissolving 10.2g of cobalt nitrate hexahydrate and 4.3g of ferrous nitrate hexahydrate in 50mL of deionized water, wherein the molar ratio of Co to Fe is 7:3. the solution was then impregnated to 6.0g of TiO by an equal volume impregnation method 2 On a support, tiO 2 Molar ratio to (Co + Fe) 1.5:1. in the above operation, co and Fe can be supported on TiO at the same time 2 On a carrier. Then roasting the mixture for 4 hours at the temperature of 600 ℃ in a muffle furnace under static air to obtain the CoFe supported TiO 2 A supported catalyst.
As a result of characterization by XRD, TEM and the like, the sizes of Co and Fe particles are very non-uniform, and agglomeration phenomenon exists, and the average particle sizes are all larger than 20nm. The catalyst was then charged into a methane reforming evaluation apparatus, and the catalyst was subjected to hydrogenation in the presence of hydrogen 2 /N 2 The evaluation was carried out after reduction at a reduction temperature of 600 ℃ for 4 hours in an atmosphere (50% by volume each, flow rate 120 mL/min). The evaluation results show that the product has CO 2 Conversion was only 50.48%, CH 4 Conversion was 55.89%, H 2 The molar ratio of the carbon to CO is 0.73, the activity of the catalyst is continuously reduced within 50h of evaluation, and finally the reaction tube is blocked due to serious carbon deposition, which indicates that the catalytic performance and the stability of the catalyst are poor. It also finally indicates that the supported catalysts are less stable than the support-coated catalysts.

Claims (6)

1. A preparation method of a core-shell catalyst for dry reforming of methane and carbon dioxide is characterized by comprising the following steps:
step 1): mixing CaO with a cobalt sourceDissolving the two materials into deionized water, stirring the mixture in a water bath at room temperature to react, and filtering the mixture to separate a product Co (OH) 2 Washing the nano-sheets to be neutral by using deionized water, and drying; dissolving CaO and an iron source into deionized water, stirring the solution in a water bath at room temperature for reaction, and filtering the reaction product to separate a product Fe (OH) 2 Washing the nano-sheets to be neutral by using deionized water, and drying;
step 2): mixing the Co (OH) obtained in the step 1) 2 Nanosheet, fe (OH) 2 Dispersing the nanosheets and the metal source M in deionized water, stirring uniformly, transferring the solution to a hydrothermal kettle for reaction, centrifuging, washing the product to be neutral by using the deionized water, and drying to obtain a CoFeM mixed hydroxide; co (OH) in the step 2) 2 Nanosheet, fe (OH) 2 The molar ratio of Co to Fe in the nanosheets is 7:3; the metal source M is at least one of titanium nitrate, aluminum nitrate and chromium nitrate, and the molar ratio of the metal source M to the sum of the moles of Co and Fe is (0.5-3) to 1; the ratio of the sum of the moles of Co and Fe to the deionized water is 1mmol: (1-6) mL;
step 3): roasting the CoFeM mixed hydroxide obtained in the step 2) in a muffle furnace to obtain a CoFeM mixed oxide;
step 4): placing the CoFeM mixed oxide obtained in the step (3) in H 2 And N 2 Is reduced under the atmosphere of mixed gas to obtain CoFe @ M x O y A catalyst.
2. The method for preparing the core-shell catalyst for dry reforming of methane and carbon dioxide according to claim 1, wherein in the step 1), the cobalt source is cobalt nitrate, the iron source is ferrous nitrate, and the cobalt source and the iron source are added in the same molar amount; the mol ratio of CaO to Co or Fe is (0.4-1.2) and the proportion of 1 Co or Fe to the deionized water solution is 1mmol: (1-4) mL.
3. The preparation method of the core-shell catalyst for dry reforming of methane and carbon dioxide according to claim 1, wherein the reaction time in the step 1) is 12-60 h; the drying temperature is 80 ℃ and the drying time is 12h.
4. The preparation method of the core-shell catalyst for dry reforming of methane and carbon dioxide according to claim 1, wherein the reaction temperature in the step 2) is 60-180 ℃ and the reaction time is 6-18 h.
5. The method for preparing the core-shell catalyst for dry reforming of methane and carbon dioxide according to claim 1, wherein the calcination in step 3) is carried out at a temperature of 600 ℃ for 4 hours.
6. The method of claim 1, wherein the step 4) is performed by using H as a catalyst, and the method comprises the step of preparing a core-shell catalyst for dry reforming of methane and carbon dioxide 2 And N 2 H in the mixed gas atmosphere of 2 And N 2 The volume percentage of the catalyst is 50 percent respectively, the reduction temperature is 400-700 ℃, and the time is 1-8 h.
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